1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2014 Oracle Co., Daniel Kiper
6 #include <linux/bitops.h>
8 #include <linux/init.h>
9 #include <linux/string.h>
12 #include <xen/xen-ops.h>
13 #include <xen/interface/platform.h>
16 #include <asm/setup.h>
17 #include <asm/xen/hypercall.h>
19 static efi_char16_t vendor[100] __initdata;
21 static efi_system_table_t efi_systab_xen __initdata = {
23 .signature = EFI_SYSTEM_TABLE_SIGNATURE,
24 .revision = 0, /* Initialized later. */
25 .headersize = 0, /* Ignored by Linux Kernel. */
26 .crc32 = 0, /* Ignored by Linux Kernel. */
29 .fw_vendor = EFI_INVALID_TABLE_ADDR, /* Initialized later. */
30 .fw_revision = 0, /* Initialized later. */
31 .con_in_handle = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
32 .con_in = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
33 .con_out_handle = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
34 .con_out = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
35 .stderr_handle = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
36 .stderr = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
37 .runtime = (efi_runtime_services_t *)EFI_INVALID_TABLE_ADDR,
38 /* Not used under Xen. */
39 .boottime = (efi_boot_services_t *)EFI_INVALID_TABLE_ADDR,
40 /* Not used under Xen. */
41 .nr_tables = 0, /* Initialized later. */
42 .tables = EFI_INVALID_TABLE_ADDR /* Initialized later. */
45 static efi_system_table_t __init *xen_efi_probe(void)
47 struct xen_platform_op op = {
48 .cmd = XENPF_firmware_info,
50 .type = XEN_FW_EFI_INFO,
51 .index = XEN_FW_EFI_CONFIG_TABLE
54 union xenpf_efi_info *info = &op.u.firmware_info.u.efi_info;
56 if (!xen_initial_domain() || HYPERVISOR_platform_op(&op) < 0)
59 /* Here we know that Xen runs on EFI platform. */
61 efi.get_time = xen_efi_get_time;
62 efi.set_time = xen_efi_set_time;
63 efi.get_wakeup_time = xen_efi_get_wakeup_time;
64 efi.set_wakeup_time = xen_efi_set_wakeup_time;
65 efi.get_variable = xen_efi_get_variable;
66 efi.get_next_variable = xen_efi_get_next_variable;
67 efi.set_variable = xen_efi_set_variable;
68 efi.set_variable_nonblocking = xen_efi_set_variable;
69 efi.query_variable_info = xen_efi_query_variable_info;
70 efi.query_variable_info_nonblocking = xen_efi_query_variable_info;
71 efi.update_capsule = xen_efi_update_capsule;
72 efi.query_capsule_caps = xen_efi_query_capsule_caps;
73 efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count;
74 efi.reset_system = xen_efi_reset_system;
76 efi_systab_xen.tables = info->cfg.addr;
77 efi_systab_xen.nr_tables = info->cfg.nent;
79 op.cmd = XENPF_firmware_info;
80 op.u.firmware_info.type = XEN_FW_EFI_INFO;
81 op.u.firmware_info.index = XEN_FW_EFI_VENDOR;
82 info->vendor.bufsz = sizeof(vendor);
83 set_xen_guest_handle(info->vendor.name, vendor);
85 if (HYPERVISOR_platform_op(&op) == 0) {
86 efi_systab_xen.fw_vendor = __pa_symbol(vendor);
87 efi_systab_xen.fw_revision = info->vendor.revision;
89 efi_systab_xen.fw_vendor = __pa_symbol(L"UNKNOWN");
91 op.cmd = XENPF_firmware_info;
92 op.u.firmware_info.type = XEN_FW_EFI_INFO;
93 op.u.firmware_info.index = XEN_FW_EFI_VERSION;
95 if (HYPERVISOR_platform_op(&op) == 0)
96 efi_systab_xen.hdr.revision = info->version;
98 op.cmd = XENPF_firmware_info;
99 op.u.firmware_info.type = XEN_FW_EFI_INFO;
100 op.u.firmware_info.index = XEN_FW_EFI_RT_VERSION;
102 if (HYPERVISOR_platform_op(&op) == 0)
103 efi.runtime_version = info->version;
105 return &efi_systab_xen;
109 * Determine whether we're in secure boot mode.
111 * Please keep the logic in sync with
112 * drivers/firmware/efi/libstub/secureboot.c:efi_get_secureboot().
114 static enum efi_secureboot_mode xen_efi_get_secureboot(void)
116 static efi_guid_t efi_variable_guid = EFI_GLOBAL_VARIABLE_GUID;
117 static efi_guid_t shim_guid = EFI_SHIM_LOCK_GUID;
119 u8 moksbstate, secboot, setupmode;
122 size = sizeof(secboot);
123 status = efi.get_variable(L"SecureBoot", &efi_variable_guid,
124 NULL, &size, &secboot);
126 if (status == EFI_NOT_FOUND)
127 return efi_secureboot_mode_disabled;
129 if (status != EFI_SUCCESS)
132 size = sizeof(setupmode);
133 status = efi.get_variable(L"SetupMode", &efi_variable_guid,
134 NULL, &size, &setupmode);
136 if (status != EFI_SUCCESS)
139 if (secboot == 0 || setupmode == 1)
140 return efi_secureboot_mode_disabled;
142 /* See if a user has put the shim into insecure mode. */
143 size = sizeof(moksbstate);
144 status = efi.get_variable(L"MokSBStateRT", &shim_guid,
145 NULL, &size, &moksbstate);
147 /* If it fails, we don't care why. Default to secure. */
148 if (status != EFI_SUCCESS)
149 goto secure_boot_enabled;
152 return efi_secureboot_mode_disabled;
155 pr_info("UEFI Secure Boot is enabled.\n");
156 return efi_secureboot_mode_enabled;
159 pr_err("Could not determine UEFI Secure Boot status.\n");
160 return efi_secureboot_mode_unknown;
163 void __init xen_efi_init(struct boot_params *boot_params)
165 efi_system_table_t *efi_systab_xen;
167 efi_systab_xen = xen_efi_probe();
169 if (efi_systab_xen == NULL)
172 strncpy((char *)&boot_params->efi_info.efi_loader_signature, "Xen",
173 sizeof(boot_params->efi_info.efi_loader_signature));
174 boot_params->efi_info.efi_systab = (__u32)__pa(efi_systab_xen);
175 boot_params->efi_info.efi_systab_hi = (__u32)(__pa(efi_systab_xen) >> 32);
177 boot_params->secure_boot = xen_efi_get_secureboot();
179 set_bit(EFI_BOOT, &efi.flags);
180 set_bit(EFI_PARAVIRT, &efi.flags);
181 set_bit(EFI_64BIT, &efi.flags);